In Organic Chemistry, Bonding refers to the process of a carbon-based molecule forming a chemical bond due to the attractive interactions between two atoms. This attraction may be seen as a consequence of the nucleophilic properties of the substituents binding to the carbon – this is because carbon usually has a net positive dipole (although there are a few exceptions).
In organic compounds, carbon is usually bonded to electronegative substituents. For example, the ketone functional group has an oxygen atom double bonded to the central carbon. Due to oxygen’s electronegativity, the electrons shared within the double bond are pulled towards the oxygen and away from the carbon. This electrostatic phenomenon causes the carbon to possess a partial positive charge. It is this dipole which makes the carbon so susceptible to many of the organic reactions where other substituents can bond to it.
For example, in a typical SN2 reaction (which proceeds in a bimolecular manner), a nucleophile attacks the electrophile (due to the partial positive charge of the carbon) causing the leaving group to leave. This creates a new covalent bond which renders the carbon more stable. However, bonding can take place at a different rate in an SN1 reaction where a carbocation forms. This would form a stronger electrostatic force between the two entities causing them to bond immediately.
The phenomenon of bonding spans the spectrum of all reactions –by using this example of a SN1 reaction, it can be seen that understanding the rationale behind this behavior is crucial to predicting the outcome of reactions as well as three dimensional arrangements of atoms within a molecule.